Adventures of an Aviatrix, in which a pilot travels the skies and the treacherous career path of Canadian commercial aviation, gaining knowledge and experience without losing her step, her licence, or her sense of humour.

Saturday, April 18, 2009

Newsflash: Engines Vulnerable to Idiots

In 2004 two Pinnacle Airlines pilots flying a leg with no passengers decided to "have some fun" and fly their CRJ200 to its published performance ceiling of 41,000'. That's a little bit like driving your car at 200 km/h, without regard for road conditions, just because the speedometer goes up that far. They exceeded the recommended climb rate, never reaching the published minimum speed for that altitude, and ran one of the engines 300 degrees above its maximum operating temperature. They also did not take into account the non-standard temperature, which lowered the performance ceiling. The airspeed was so low that the stick shaker was activating, and both engines flamed out. They recovered the stall and attempted to restart the engines, but could not, and without the engines they couldn't hold altitude. They did not inform ATC of the extent of their problem and bypassed four possible landing airports before attempting an off airport landing in the dark. Both were killed and the aircraft was destroyed in the ensuing crash.

For more information see the NTSB report and the cockpit voice recording transcript. The NTSB called it unprofessional behavior poor airmanship and inadequate training. They were even nominated for a Darwin Award. But that's just background. Their escapade is not what this blog entry is about. It's that the engine manufacturer has taken some blame.

No, Pinnacle didn't sue the pilots' families and initial training organization to recover the cost of the fine airplane they lost. The families of the pilots sued the engine manufacturer for not making it clearer that if you did unspeakably stupid things with their engines, they were unlikely to continue functioning. And now the FAA has mandated changes to the General Eletric CF34 turbofan engine based on this crash.

The FAA have concluded that "excessive" friction between the static and rotating portions of a certain engine seal, under certain high-power, high-altitude conditions is unsafe and must be corrected. This is a mandatory airworthiness directive, so over two thousand such engines will have to undergo a modification, costing their operators ten hours per airplane. GE says it respectfully disagrees that there is an unsafe condition in the engine. They tried to get the FAA to explain it as a measure to reduce friction to facilitate an engine start after a high-altitude dual flameout, "an engine condition that is extremely rare," but the FAA declined.

It's true that these engines were very sensitive to the high angle of attack they were subjected to, and the pilots didn't realize that. The piston engines on training airplanes can be run at full power during a stall and the airplane doesn't care. After a period of high angle of attack and low speed, the reduced engine cooling will cause a rise in engine temperature, but the engine isn't dependent on the airflow for its very rotation the way the turbofan is. Once the engines stopped rotating they were going to be very hard to restart. Perhaps someday someone else will get these engines flamed out in coffin corner and the modification will keep them turning long enough to get them to safety.

I think the FAA decision is unfortunate, not so much over twelve thousand hours of upgrade work on CF34 engines, but that the wording of the AD may help the legal case against the company. In the 1980s, general aviation aircraft simply stopped being manufactured because the companies couldn't bear the legal costs of survivors suing them when pilots (or in some cases non-pilots in stolen airplanes!) asked airplanes to do things they weren't designed to do, and died. Jim Campbell of the Aero-News Network has a more strongly worded opinion on the situation.

14 comments:

And here-in lies the major flaw in the modern legal systems found in many parts of the world. The judge didn't have the guts to stand up and say to the families:

"Your kids were being stupid and deserved what they got. Get the frak outta my court room!"

A just & democratic society relies on its members taking responsibility for the consequences of their actions (including the stupid/illegal ones). I can't believe that these families are allowed to persue this :(

This is one of the moments when engineers get headaches and nausea. Not that everything designed by engineers is perfect, much is even quite the contrary of perfect, but... (and this is a big but!)

To me, the reasoning from the behaviour that led to this crash sounds like: If the aircraft would have had higher limitations because of improved engines, the pilots would have pushed those limits and experienced some sort of failure.

Those who design technology and those who apply technology don't share a give-and-take relationship, much rather, they share one of give-and-give. The best piece of machinery will give up if it's not maintained and used well.

I sometimes wonder if products as incredibly dangerous as matches and candles could be introduced into the marked these days, with these days' laws.

The Darwin award winners simply provided the NTSB with a good reason to spend time and money investigating the systems. NTSB determined in the investigation that these particular engines might not reliably restart in all the conditions that certification assumes/implies/expects that they will. They determined that GE was making claims they didn't have the engineering/flight test data to back up. The FAA followed up and an AD resulted.

Try reading Appendix E, included with the full report...for some reason not linked here.

PDF link:http://www.ntsb.gov/publictn/2007/AAR0701.pdf

The AD is to protect the paying public from death and injury. Not every high altitude flameout is due to stupid pilot tricks. Multiple engine flameouts necessitating restarts have happened before and will happen again. I'd prefer to be strapped into the aircraft where the restart is guaranteed by design, analysis, and testing as opposed to hand waving.

Asking the FAA to parse its comments so as to lower their value to lawyers is bizarre to me. The FAA is in the business of regulating aircraft and air travel, not managing product liability costs. The latter problem is properly left to Congress and the courts.

Reading the full NTSB report, the pilots were cowboys on this flight. It could be fun to get right up to maximum ceiling, but stay within the envelope top get there. And getting a momentary climb rate of 10,000 fpm (as they did shortly after takeoff) is yet more indication that they were little more than 16yo's with daddy's car for the first time on Friday night. It's all fun until someone pokes their eye out. And, at least in this case, Darwin was right.

That the NTSB want to make the engines better is a separate, and good, topic, for all the reasons stated by Garrett.

And the reason that snakes do not bite lawyers is one of professional courtesy. I hope that none of the companies succombs to greenmail, and the judge makes the families and their legal firm pay all costs, and reimburse them for their legal bills. However, in the US it seems that you can be as much of an idiot as you want, but you still get to sue someone when you have a mishap.

I was trying to address the separate issue of the engines when I wrote "Perhaps someday someone else will get these engines flamed out in coffin corner and the modification will keep them turning long enough to get them to safety," but I appreciate Garrett making that clearer, and linking to the full report.

AIUI Pinnacle would be paying teenage wages for these pilots. In my line of work, if you habitually pay peanuts you're apt to find some monkeys in your workforce.

As for the families, would there be an insurance company involved anywhere? As in, "We sold you insurance against losing your breadwinner, but the small print says you're not covered if he was to blame. So you can starve or sue us, or anyway sue someone!"Even lawyers struggle with insurance companies.

I could be wrong but I read once that one of the reasons you see people suing everybody involved after things like this is that you only have a certain time limit in which a lawsuit can be brought about against a company. So the train of thought is if the investigation finally concludes that the aircraft or engines were to blame, then the statute of limitations has not expired (as investigations like these can sometimes take a long time to complete). That is why for air crashes you usually see everybody get sued no matter the apparent cause at the time is. I'm not saying I agree or condone such behavior (or sometimes not even the system that is in place), but just saying that I think there is also some kind of legal reasoning for doing it beyond just displacing blame and greed.

1. There is a limitation for amount of time which can pass between the event and the time at which the lawsuit can be filed,

2. Lawsuits are filed against everybody who could possibly be at fault, so that there is no room in court for those who are sued to blame those who are not sued (and thus wiggle off the hook). Better to sue everybody, and let them argue before the judge as to why they are not responsible,

3. There is competition amongst lawyers, and as soon as a Bad Thing happens, lawyers start contacting the agrieved and making their case as to why they are the best lawyers on the planet and how rich you are going to be once you win your guaranteed case. You want to sign up with one and get the case filed to to get the phone to stop ringing.

4. You want to make sure that you include several parties in the case who have deep pockets. So while the family of the dead co-pilot might include the estate of the dead pilot in the lawsuit, you won't get much money from him so you also sue the major corporations. As a different example, while you might want sue the school bus driver, you also make sure you sue the school board and the manufacturers of the bus.